


Offbeat

by BlueNeutrino



Series: Tricuspid [2]
Category: Supernatural
Genre: Anal Sex, Cardiophilia, Dom Castiel, Heartbeat Kink, Light Dom/sub, M/M, Multi, Mutual Masturbation, Sub Dean, Sub Sam, Wincestiel - Freeform
Language: English
Status: Completed
Published: 2014-09-13
Updated: 2014-09-13
Packaged: 2018-02-17 07:10:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,890
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2300921
Author URL: https://archiveofourown.org/users/BlueNeutrino/pseuds/BlueNeutrino
Summary: <blockquote class="userstuff">
              <p>Sequel to "Double Bass". Castiel plays another game with Sam and Dean's hearts, this time with a twist.</p>
            </blockquote>





	Offbeat

**Author's Note:**

> Since a couple of people requested a similar fic to the previous one with mutual masturbation between Dean and Sam, here it is.

The brothers face each other, kneeling naked upon the bed so that their foreheads almost touch. Their breaths are thunderous in the silence: ragged and heavy, each exhale pumping out the feverish heat of their bodies into the air before being drawn into the other’s lungs. Green eyes bore into hazel as neither dares to look away, not chancing to look without permission at the unclothed figure watching them.

Castiel smiles. He reaches out a hand to run his fingers through Sam’s hair, gently smoothing the sweat-damp strands. “Good boys,” he softly praises, moving to lightly run his knuckles down Dean’s cheek. “Such good boys for me.”

Sam and Dean keep their eyes locked on each other as Castiel pulls his hand away, and then Dean is first to feel the cold press of a stethoscope against his chest. The metal is wonderfully cool against his burning skin, but by the time Castiel pulls it away, Dean’s body heat has flooded the steel. The angel flips the head over in the narrow space between the brothers’ bodies and then places it against Sam’s chest, pre-warmed by Dean’s skin. “Your hearts are working so hard,” the angel says, his voice a low rumble. “So loud and powerful, but I want to see you both push them further.”

Neither is sure if a response is required, by Sam mumbles out a, “Yes, Castiel,” prompting Dean to do the same.

Even if it wasn’t necessary, Cas doesn’t seem displeased. He pulls the stethoscope away again and then assumes a colder tone. “Sam, pick up Dean’s cock,” he orders, and Sam obediently reaches out to grasp the thick column of flesh protruding upwards from between Dean’s thighs. A heavy gasp escapes Dean’s lips as Sam’s fingers close tightly around him, but he doesn’t have permission to do anything more. “Dean, get a good hold on Sam’s.”

With an excited lick of his lips, Dean reaches over to firmly take hold of his brother’s erection, and Sam barely manages to suppress his squirms. They both kneel there, completely still for a couple of moments as they await their next instruction.

“You know this game,” Castiel eventually says, leaning closer to the pair of them. Still neither brother turns his head. “I want you to get your strong little hearts racing, but this time you’re going to take control of each other’s. Sam, you make sure you do a good job of really pumping your brother’s cock, and Dean, you do the same for Sam. Whichever of you gets the other’s heart to beat fastest will be getting a treat tonight. Of course, I hardly need point out that whichever one of you fails to get your brother’s heart pounding satisfactorily will not get to come.”

They both nod, murmuring their understanding, and then Cas raises the head of the stethoscope between their chests again. It’s a dual head, and Cas is pinching it between the index and middle fingers of his right hand so that the bell points towards Dean and the diaphragm towards Sam. He keeps it hovering between them until he gives his instructions. “Alright, off you go.”

They each begin, hands frantically working to pleasure each other as the sound of skin roughly sliding over skin joins the noises of heavy breathing. Cas grins as he lowers his eyes to watch. It’s interesting to observe their differences in technique: they each know what the other likes. Sam is fast and rough, his large hand pulling hard on Dean’s cock, while Dean is adapting himself to dealing with a dick slightly larger than his own. He’s paying more attention to the pressure in his fingertips and the way he angles his strokes, and the shuddering of Sam’s breath says he’s doing a good job. Cas wants to confirm that.

The angel shifts his hand backwards to press the diaphragm to Sam’s chest, and he’s immediately able to pick up the thunderous sound of the younger brother’s heartbeat. “You just keep that up, Dean,” Cas encourages before shifting his hand the other way to settle the bell to Dean’s skin. Dean’s heart pounds in his ears, perfectly fast and strong, and Cas delights in the sounds of what they’re doing to each other. He’s got the stethoscope head twisted into the bell position, making that noise louder and better quality, and in the interest of fairness he flips the head to listen to Dean’s heart with the diaphragm. It’s still wonderfully fast, but the sound is duller, and so Cas shifts the head again to press the bell to Sam’s chest. He wishes he could get equal sound quality on both sides of the head simultaneously, but this will work for what he has in mind.

“Get closer to each other,” he growls at them. “I know you want to feel each other’s bodies, so go right ahead. Get your faces to touch… your mouths to touch… your dicks…”

They do as they’re told, starting to lean closer, soft grunts punctuating the spaces between their ragged breaths. Cas can feel the intense heat from both their chests as he hold his hand between them. “Come on,” he murmurs as Sam and Dean touch foreheads, still staring into each other’s eyes. The ends of their cocks bang together as they continue to jerk off. “I want you to do whatever will make your hearts pound hardest. Kiss.”

They do. Sloppily. Wet smacking sounds break the air as their mouths lock together, for the first time closing their eyes as they become lost in nothing but the feel of each other. Cas stares, watching Dean suck on Sam’s bottom lip, Sam drawing Dean’s tongue into his mouth…both lengths of pink muscle locking and tangling together as they breach the seal of each other’s lips. It’s almost like watching a beating heart, Cas muses, as they both fall into a rhythm of sucking and opening their mouths like valves pumping blood. The angel’s own lips part and he runs his tongue over them as he contemplates that image. He can still hear Sam’s heartbeat in the earpieces, and it’s making his own dick throb.

“ _Closer,_ ” he orders forcefully. “Press your hearts together. I’m listening.”

Without their lips ever breaking contact or the motion of their hands faltering, Sam and Dean lean their upper bodies towards each other. Cas feels his hand become sandwiched between them as their chests make contact, wonderfully warm, and then each side of the stethoscope is pressed against one of them. The sound that hits Cas’ ears is incredible.

Sam’s heart still sounds loudest, pounding into the bell of the stethoscope, but between each racing beat Cas can hear the undertone of Dean’s heart thudding in the diaphragm. Both heartbeats are loud and fast, harmonising perfectly with each other, and Cas thinks he could sit here and listen to it forever if they didn’t have a game to play. But they’re both getting close to finishing, and Cas thinks he can only let them have a couple more minutes.

He can hear the rhythms of their hearts slightly shifting relative to each other as Sam’s tugs minutely pick up pace, and then after a few seconds the angel is amazed to hear both their pulses sync up up completely. It sounds wonderful: each beat amplified by the force of two hearts and thundering with astonishing speed in his ears. Cas’ own dick gives a throb, and he knows if he doesn’t cut this short one or both of them is about to come. “Stop,” he orders forcefully, and he can feel the whine that comes from Dean’s chest as Sam’s hand goes still. “You stay right where you are. Don’t move.”

They obediently leave their hands on the other’s dick, but no longer move. Tension is evident on both their faces, but neither attempts to push the rules. Cas is pleased. “You know I can hear both your hearts, don’t you?” he says softly. “Both so loud and fast for me. Can you feel it? Both your hearts are beating perfectly in time. That’s because you’re such good brothers, and such good boys. Although it does make this game rather difficult…”

Sam whines quietly then, and Cas chuckles. “Alright, lean back. I’m going to listen to each of you separately.”

They do so, separating by just a few inches, which allows Cas to explore each of their chests with the stethoscope individually. He starts with Dean, flipping the head over in order to hear the racing rhythm of Dean’s heart with the bell again. It’s still loud and incredibly fast, maybe pushing 180 beats per minute, but Cas doesn’t think it matches up to Sam’s at his loudest. “Alright, Dean,” the angel mutters after having listened to all of Dean’s valves. “That’s very good. I’m just going to take a listen to your brother.” He then shifts the head round again to push the bell back into Sam’s chest. He’s met with more resistance from Sam’s muscles than Dean’s slightly softer build, but it’s confirmed that Sam’s heart still sounds louder.

Cas sighs. “Oh Sam, your heart always puts up such a good show when we play this game, doesn’t it? It’s such a powerful little thumper, but you know that means this time Dean gets to win?”

Sam only looks slightly disappointed. “I know. He deserves to,” he mutters, giving Dean a small smile. Sam usually wins whenever they play this game, no matter how hard he tries to get his heart to slow down, and he’s pleased that this time Dean will get the treat for once.

Cas leans in to press a kiss to Sam’s temple before pulling the stethoscope away and fixing his attention on Dean once again. “Your brother’s so kind, isn’t he, Dean?” he says, and Dean nods.

“Yes, Castiel.”

“That means you get your treat now. Would you like to know what it is?”

Dean swallows and glances down. He’s excited and more than a little nervous, but it feels strange to him that for once Cas is going to be rewarding him when it’s Sam’s heart that’s beating strongest. It still amazes him that he was the one who was able to do that to Sam’s heart. “Yes please, Castiel,” he answers in an eager but quiet voice.

“I’m going to fuck you good and rough,” Cas growls, and Dean feels his already aching cock give another throb. “But I’m a little worried about your heart. Even when you’ve got Sam jerking you, you still can’t get it to beat as loud as his. I think it’s because you eat too much junk food.”

Dean can feel himself blushing. “I’m sorry, Cas. I can cut down on the burgers and the pie for you if you want…”

Castiel quickly silences him with a kiss. “I wouldn’t ask that of you, Dean,” the angel says, pulling back with a small smile. “It just means that we have to keep an extra close eye on your heart to make sure you’re healthy. So…” He pulls off the stethoscope and then thrusts it towards Sam, who takes hold of it and grins as he realises what it means. “While I’m fucking you, I’m going to make sure you’re brother listens to your heartbeat.”

Sam looks thrilled that Cas is going to involve him in this at all, as does Dean. Normally the loser is only allowed to do so much as watch.

“Now then,” Cas continues, giving Dean’s shoulders a shove so that he falls back onto the bed. Dean stares up at him, lips parted and pupils blown wide with arousal. “Let’s give you your treat.” The angel slides his hands under Dean’s thighs and pulls him further down the bed, spreading Dean’s legs apart to expose his hole. The hunter’s stiff cock rolls against his stomach from the movement, and Cas licks his lips at the sight of the shining trail of precome it leaves smeared over Dean’s abdomen. He flashes Dean a salacious grin and then holds an expectant hand out towards Sam.

Sam knows this is part of his penalty for losing, but, all things considered, Cas is being very kind, so Sam reaches for the bottle of lube on the nightstand and hands it over to him without comment. Cas flips the cap open and then squirts a generous amount onto his fingers, which he proceeds to smother over his cock before reaching down to start slicking up Dean’s hole. Dean gasps and writhes a little as the first digit presses inside him, and Sam shoots Cas a look.

“Castiel, should I start listening?” he asks tentatively.

The angel doesn’t take his eyes off of Dean as he answers. “Yes. Get his head in your lap and the stethoscope on his chest.”

Sam does as he’s told, shifting himself to get behind Dean’s head. Dean helpfully raises his upper body a little to allow Sam to sit underneath him, and then leans back against his brother’s crossed legs. His spine settles against the cross of Sam’s ankles while his shoulders rest comfortably just above Sam’s knees, keeping his chest elevated. The back of his head bangs against Sam’s cock, and Sam bites his lip as he feels Dean’s soft hair tickle the sensitive skin. The younger brother casts an anxious glance at Cas, wondering if he’ll be ordered to adjust himself, but the angel just seems amused as he watches them. Trying not to think about the sensations on his dick, Sam fits the stethoscope into his ears and then settles the head down over Dean’s chest. He can audibly hear that his brother’s heart is now racing faster than his own, still pumped with excitement while Sam’s has had time to settle. “It’s very fast, Castiel,” Sam reports back to the angel.

“Good,” Cas replies with a grin, getting himself in position so that his cockhead is pushed up against Dean’s entrance. He stares down at Dean, arousal painted plain on his face while Dean stares back. “You ready for this, Dean?”

Dean nods emphatically, forcing Sam to bite his lip as he feels Dean’s hair tickle his cock again.

Without further delay, Cas slides home.

Sam swears he hears the kick in Dean’s heart before any cries actually leave his brother’s lips, but a split second later Dean is crying out as he feels himself completely filled. Cas takes it steady at first, easing himself in down to the root, but when he slides out again to begin thrusting his movements immediately begin to quicken. As promised, Castiel is rough, each harsh snap of his hips prompting Dean to scream and rocking the bed so that Sam himself gasps, tormented by the motion of Dean’s body while the heartbeat thundering in his ears gets louder.

Dean’s hands fist at the sheets, clearly itching to grasp onto his own cock and complete the onslaught of pleasure wracking his body, but he _can’t._ Not without permission…

A soft whine keens in his throat. “Cas, _please…_ ” he begs, but it isn’t permission he needs anymore when he suddenly feels Cas’ hand close around his dick, gripping as tightly as Sam had, and then the angel delivers a few hard strokes in time with his thrusts.

Dean is so close to the edge already that that’s all it takes to finish him. He gives a final yell and comes, white strings pulsing out onto his torso and over the back of Sam’s hand, where the younger brother is still holding the stethoscope in place over Dean’s wildly thudding heart.

Cas gives his own grunt of delight as he feels the shockwave coursing through Dean’s body, causing the hunter’s muscles to clench down tightly around him, and then a few seconds later he himself finishes too. He spills himself into Dean, eyes fluttering shut as he rides out his orgasm, and then, spent, he pulls out and flops down beside the brothers on the bed.

“How does his heart sound?” the angel mumbles to Sam after a few seconds, face buried in the sheets.

Sam smiles as he answers. “It went wild for you,” he’s pleased to say, sliding himself out from under Dean, who’s somewhat limp and dazed in the aftermath. Sam settles himself down on the bed beside the pair of them, stethoscope still resting over Dean’s heart. “And it sounds healthy enough, but you’re right: we should keep an eye on it.”

Cas raises his head a little, a contented look on his face as he gazes over Dean’s sated body to meet eyes with Sam. “Let’s both do that, then,” he says warmly, reaching a hand out to settle over where Sam has his own holding the stethoscope in place. The angel affectionately strokes his thumb over Sam’s knuckles, closing his eyes as the three of them settle down just to take some time to breathe. The angel has the heel of his hand resting against Dean’s ribs, and he can feel Dean’s heart still banging madly beneath them. He wonders what it must sound like in Sam’s ears, but that’s something he’s going to let the younger Winchester enjoy for himself until Dean’s heart eventually slows down again, and they know it’s time for the three of them to sleep.


End file.
